In the case of using biological authentication for identity verification of persons of an unspecified number, a degree of proficiency in using an authentication apparatus varies between the persons. A user with a low degree of proficiency does not have much knowledge about a proper showing position or showing attitude of a living body. Therefore, there are some cases where the user shows the living body in an improper position or attitude and the precision of authentication decreases. Therefore, biological authentication with a high usability that is capable of performing authentication at a high precision even in the case where there is a large variation in showing positions and showing attitudes of a living body is desired.
PTL 1 describes an individual authentication apparatus and so forth that cause one finger to be shown in a predetermined showing region and control a light source for irradiation in accordance with a variation in the attitude of the finger and with a showing position of the finger.